A mid-luteal phase comparison of peritoneal fluid volume and its content of PGF2 alpha and PGE2 in women with minimal stage endometriosis and a normal pelvis.

The study was carried out following the approval of our Hospital Ethics Committee and an informed patient consent. Samples of peritoneal fluid were collected from the Pouch of Douglas at laparoscopy from 32 subjects with minimal stage endometriosis (MSE) and 16 without any visible signs of endometriosis (normal group). All the subjects were in 20 to 23 day period of their menstrual cycle which was histologically confirmed. The endometriosis score was estimated according to the American Fertility Score, 1985 and the fluid samples were collected in tubes containing heparin/indomethacin and standing in ice. The samples were estimated for volume, erythrocyte count, prostaglandin(PG) F2 alpha, and PGE2. Radioimmunoassay techniques were used for the estimation of PGs. Prostaglandin F2 alpha, was measured in its parent form while PGE2 was converted into bicyclic-PGE2 before estimation. The results indicate that the peritoneal fluid in women with MSE has higher than normal levels of PGF2 alpha and lower than normal levels of PGE2 and its PGE2: PGF2 alpha ratio is also below normal. There is no difference in the volume of peritoneal fluid in the two groups. Provided the fluid sample is not contaminated with abdominal blood its erythrocyte count is not related to its prostaglandin content.